The invention relates to the cooling of electronic components and, in particular, to the cooling of electronic components housed within an electronics shelf.
The speed of electronic components steadily accelerates and, at the same time, increase in density. Additionally, more components are often placed within a single housing than ever before. All these factors: increased speed of operation, increased density of circuitry within a component, and the increased density of components within a housing, contribute to higher operating temperatures. As the temperature of electronic components increase, their reliability decreases. Heat equals failure and it must be dissipated in order to ensure the proper operation of systems that employ components. Various approaches to the cooling of electronic components have been pursued. Forced fluid cooling is described, for example in, U.S. Pat. No. 4,851,965 issued to Garbuzda et al (Garbuzda), which is hereby incorporated by reference. Garbuzda describes the use of jet impingement of air onto the heat generating component through separate plenums. A circuit pack with inboard jet cooling is described in U.S. Pat. No. 5,067,047 issued to Azar, which is hereby incorporated by reference. It has also been suggested that air can be blown onto the components through holes in the enclosures or shields surrounding the circuit components (see, for example, U.S. Pat. No. 4,393,437 issued to Bell et al and U.S. Pat. No. 4,408,255 issued to Adkins, both of which are hereby incorporated by reference. It has been suggested that holes in the circuit boards themselves could allow air to impinge on components in circuit packs which are stacked (see, for example, U.S. Pat. No. 4,399,484 issued to Mayer, which is hereby incorporated by reference).
An electronic cooling system that provides efficient and substantial cooling potential for electronics contained within an electronics shelf would be particularly desirable.
An electronics cooling system in accordance with the principles of the present invention is directed at electronics that are housed in an electronics shelf. One example of such a shelf is sometimes referred to as a card cage. A card cage is designed to accept printed circuit boards that include electronics components mounted on the boards, with the components interconnected by printed circuit patterns on and within the circuit boards. In accordance with the principles of the present invention one or more impingement plates, each of which includes one or more apertures, is located within the card cage adjacent to one or more of the circuit boards within the card cage.
Channels are formed on either side of an impingement plate (which includes apertures) running from top to bottom and from back to front of the card cage. On a first side of the impingement plate a first channel is formed between the impingement plate and the circuit card that is to be cooled with the aid of the impingement plate. A second channel, on the other, second, side of the impingement plate, may be formed between the impingement plate and another circuit board, and a card cage wall, or with another impingement plate, for example. An ingress path in the form of one or more ingress apertures in the card cage permits a cooling fluid to be forced into the first channel. With no apertures other than those in the impingement plate for egress, the fluid is forced through the apertures toward the circuit board that is to be cooled. An egress path, in the form of one or more egress apertures in the card cage, permits the cooling fluid to escape the second channel. The ingress apertures may be located at the top or bottom of the card cage, for example. Similarly, the egress apertures may be located at the top or bottom of the card cage.